[LTP] [PATCH v1] msync04.c: Use direct IO to verify the data is stored on disk

[Jan Kara]

On Thu 30-05-24 00:40:29, Wei Gao wrote:
> Signed-off-by: Wei Gao <wegao@suse.com>
> Suggested-by: Jan Kara <jack@suse.cz>

Looks good to me! Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  testcases/kernel/syscalls/msync/msync04.c | 56 +++++++++++++----------
>  1 file changed, 33 insertions(+), 23 deletions(-)
> 
> diff --git a/testcases/kernel/syscalls/msync/msync04.c b/testcases/kernel/syscalls/msync/msync04.c
> index 1718bd7dc..c0580d1b0 100644
> --- a/testcases/kernel/syscalls/msync/msync04.c
> +++ b/testcases/kernel/syscalls/msync/msync04.c
> @@ -11,6 +11,7 @@
>   * is no longer dirty after msync() call.
>   */
>  
> +#define _GNU_SOURCE
>  #include <errno.h>
>  #include "tst_test.h"
>  
> @@ -43,10 +44,35 @@ static uint64_t get_dirty_bit(void *data)
>  	return pageflag_entry & (1ULL << 4);
>  }
>  
> -static void test_msync(void)
> +static void verify_mmaped(void)
> +{
> +	void *buffer = SAFE_MEMALIGN(getpagesize(), getpagesize());
> +
> +	tst_res(TINFO, "Not see dirty bit so we check content of file instead");
> +	test_fd = SAFE_OPEN("msync04/testfile", O_RDONLY | O_DIRECT);
> +	SAFE_READ(0, test_fd, buffer, getpagesize());
> +
> +	char *char_buffer = (char *)buffer;
> +
> +	if (char_buffer[8] == 'B')
> +		tst_res(TCONF, "write file ok but msync couldn't be tested"
> +				" because the storage was written to too quickly");
> +	else
> +		tst_res(TFAIL, "write file failed");
> +}
> +
> +static void verify_dirty(void)
>  {
> -	char buffer[20];
> +	TST_EXP_PASS_SILENT(msync(mmaped_area, pagesize, MS_SYNC));
> +
> +	if (TST_RET == 0 && !get_dirty_bit(mmaped_area))
> +		tst_res(TPASS, "msync() verify dirty page ok");
> +	else
> +		tst_res(TFAIL, "msync() verify dirty page failed");
> +}
>  
> +static void test_msync(void)
> +{
>  	test_fd = SAFE_OPEN("msync04/testfile", O_CREAT | O_TRUNC | O_RDWR,
>  		0644);
>  	SAFE_WRITE(SAFE_WRITE_ANY, test_fd, STRING_TO_WRITE, sizeof(STRING_TO_WRITE) - 1);
> @@ -55,27 +81,11 @@ static void test_msync(void)
>  	SAFE_CLOSE(test_fd);
>  	mmaped_area[8] = 'B';
>  
> -	if (!get_dirty_bit(mmaped_area)) {
> -		tst_res(TINFO, "Not see dirty bit so we check content of file instead");
> -		test_fd = SAFE_OPEN("msync04/testfile", O_RDONLY);
> -		SAFE_READ(0, test_fd, buffer, 9);
> -		if (buffer[8] == 'B')
> -			tst_res(TCONF, "write file ok but msync couldn't be tested"
> -				" because the storage was written to too quickly");
> -		else
> -			tst_res(TFAIL, "write file failed");
> -	} else {
> -		if (msync(mmaped_area, pagesize, MS_SYNC) < 0) {
> -			tst_res(TFAIL | TERRNO, "msync() failed");
> -			goto clean;
> -		}
> -		if (get_dirty_bit(mmaped_area))
> -			tst_res(TFAIL, "msync() failed to write dirty page despite succeeding");
> -		else
> -			tst_res(TPASS, "msync() working correctly");
> -	}
> -
> -clean:
> +	if (!get_dirty_bit(mmaped_area))
> +		verify_mmaped();
> +	else
> +		verify_dirty();
> +
>  	SAFE_MUNMAP(mmaped_area, pagesize);
>  	mmaped_area = NULL;
>  }
> -- 
> 2.35.3
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR